Comb and partial interlace-based sidelink feedback channel transmission

Abstract

Certain aspects of the present disclosure provide techniques for techniques for providing sidelink feedback. Certain aspects provide a method for wireless communication by a first user equipment (UE). The method generally includes receiving, from a second UE, one or more sidelink data messages and transmitting, to the second UE, via a first sidelink feedback channel resource, a first feedback message comprising one or more feedback bits associated with the one or more sidelink data messages, wherein: the first sidelink feedback channel resource comprises a first partial interlace group of a first interlace group of resource blocks, and the first partial interlace group comprises at least two first resource blocks.

What is claimed is: 
     
       1. An apparatus configured for wireless communications, comprising:
 one or more memories comprising processor-executable instructions; and 
 one or more processors configured to execute the processor-executable instructions and cause the apparatus to:
 receive signaling that includes a configuration of:
 a first resource pool with a plurality of sidelink feedback channel resources, wherein:
 the first resource pool comprises a plurality of interlace groups, 
 each of the plurality of interlace groups comprises a plurality of partial interlace groups, and 
 each of the plurality of partial interlace groups comprises at least two resource blocks, and 
 
 an amount of resource blocks for each of the plurality of partial interlace groups; 
 
 receive, from a user equipment (UE), one or more sidelink data messages during a time period having a duration of a first number of slots that is greater than one; and 
 transmit, to the UE, via a first sidelink feedback channel resource included in the first resource pool, a first feedback message comprising one or more feedback bits associated with the one or more sidelink data messages, wherein:
 the first sidelink feedback channel resource occupies resource elements from at least two resource blocks transmitted in a comb pattern in a frequency domain, and 
 the at least two resource blocks belong to a first interlace group of the plurality of interlace groups. 
 
 
 
     
     
       2. The apparatus of  claim 1 , wherein the resource elements from one or more resource blocks transmitted in the comb pattern in the frequency domain comprise the resource elements transmitted:
 only every second subcarrier in the frequency domain; 
 only every fourth subcarrier in the frequency domain; 
 only every sixth subcarrier in the frequency domain; or 
 only every twelfth subcarrier in the frequency domain. 
 
     
     
       3. The apparatus of  claim 1 , wherein the one or more processors are configured to execute the processor-executable instructions and cause the apparatus to select a cyclic shift to convey a value of each of the one or more feedback bits. 
     
     
       4. The apparatus of any  claim 1 , wherein:
 the first sidelink feedback channel resource occupies the resource elements from at least two resource blocks, and 
 the at least two resource blocks belong to a first interlace group of resource blocks. 
 
     
     
       5. An apparatus configured for wireless communications, comprising:
 one or more memories comprising processor-executable instructions; and 
 one or more processors configured to execute the processor-executable instructions and cause the apparatus to:
 receive, from a user equipment (UE), a sidelink data message during a time period having a duration of a first number of slots that is greater than one, wherein the sidelink data message is received over a first subchannel or a first frequency interlace in a first slot; 
 select a first sidelink feedback channel resource from a first plurality of sidelink feedback channel resources in a first resource pool based on:
 at least one of a first identifier associated with the UE or a groupcast identifier associated with the sidelink data message; and 
 the first subchannel or the first frequency interlace over which the sidelink data message is received in the first slot, wherein:
 the first sidelink feedback channel resource occupies resource elements from one or more resource blocks transmitted in a comb pattern in a frequency domain; and 
 
 
 transmit, to the UE, via the first sidelink feedback channel resource, a first feedback message comprising a feedback bit associated with the sidelink data message. 
 
 
     
     
       6. The apparatus of  claim 5 , wherein the resource elements from one or more resource blocks transmitted in the comb pattern in the frequency domain comprise the resource elements transmitted:
 only every second subcarrier in the frequency domain; 
 only every fourth subcarrier in the frequency domain; 
 only every sixth subcarrier in the frequency domain; or 
 only every twelfth subcarrier in the frequency domain. 
 
     
     
       7. The apparatus of  claim 6 , wherein the one or more processors are configured to execute the processor-executable instructions and cause the apparatus to select a cyclic shift to convey a value of the feedback bit. 
     
     
       8. The apparatus of any  claim 6 , wherein:
 the first sidelink feedback channel resource occupies the resource elements from at least two resource blocks, and 
 the at least two resource blocks belong to a first interlace group of resource blocks. 
 
     
     
       9. An apparatus configured for wireless communications, comprising:
 one or more memories comprising processor-executable instructions; and 
 one or more processors configured to execute the processor-executable instructions and cause the apparatus to:
 receive, from a user equipment (UE), one or more sidelink data messages during a time period having a duration of a first number of slots that is greater than one; 
 select a first sidelink feedback channel resource from a first plurality of sidelink feedback channel resources in a first resource pool based on at least one of a first identifier associated with the UE or a groupcast identifier associated with the one or more sidelink data messages, wherein:
 the first resource pool comprises a plurality of interlace groups, 
 each of the plurality of interlace groups comprises a plurality of partial interlace groups, 
 each of the plurality of partial interlace groups comprises at least two resource blocks; 
 an amount of the first plurality of sidelink feedback channel resources in the first resource pool is based, at least in part, on one or more of an amount of the plurality of partial interlace groups in the first resource pool, an amount of comb patterns available in a frequency domain, or an amount of cyclic shift pairs per comb pattern; and 
 the first sidelink feedback channel resource occupies resource elements from one or more resource blocks transmitted in a comb pattern in the frequency domain; and 
 
 transmit, to the UE, via the first sidelink feedback channel resource, a first feedback message comprising one or more feedback bits associated with the one or more sidelink data messages. 
 
 
     
     
       10. The apparatus of  claim 9 , wherein the resource elements from one or more resource blocks transmitted in the comb pattern in the frequency domain comprise the resource elements transmitted:
 only every second subcarrier in the frequency domain; 
 only every fourth subcarrier in the frequency domain; 
 only every sixth subcarrier in the frequency domain; or 
 only every twelfth subcarrier in the frequency domain. 
 
     
     
       11. The apparatus of  claim 9 , wherein the one or more processors are configured to execute the processor-executable instructions and cause the apparatus to select a cyclic shift to convey a value of each of the one or more feedback bits. 
     
     
       12. The apparatus of any  claim 9 , wherein:
 the first sidelink feedback channel resource occupies the resource elements from at least two first resource blocks, and 
 the at least two first resource blocks belong to a first interlace group of resource blocks of the plurality of interlace groups. 
 
     
     
       13. An apparatus configured for wireless communications, comprising:
 one or more memories comprising processor-executable instructions; and 
 one or more processors configured to execute the processor-executable instructions and cause the apparatus to:
 receive, from a user equipment (UE), multiple sidelink data messages during a time period having a duration of a first number of slots that is greater than one; 
 select a first sidelink feedback channel resource from a first plurality of sidelink feedback channel resources in a first resource pool based on at least one of a first identifier associated with the UE or a groupcast identifier associated with the multiple sidelink data messages, wherein:
 the first sidelink feedback channel resource occupies resource elements from one or more resource blocks transmitted in a comb pattern in a frequency domain; and 
 
 transmit, to the UE, via the first sidelink feedback channel resource, a first feedback message comprising multiple feedback bits associated with the multiple sidelink data messages, wherein the multiple feedback bits comprise at least one feedback bit for each slot of the time period. 
 
 
     
     
       14. The apparatus of  claim 13 , wherein the multiple feedback bits comprise a feedback bit that is not associated with any sidelink data message. 
     
     
       15. The apparatus of  claim 14 , wherein the feedback bit that is not associated with any sidelink data message indicates a negative acknowledgement. 
     
     
       16. The apparatus of  claim 13 , wherein:
 the apparatus is configured with multiple resource pools including the first resource pool, and 
 each of the multiple resource pools comprises one of:
 a plurality of sidelink feedback channel resources which occupy different partial interlaces; 
 a plurality of sidelink feedback channel resources which occupy resource elements from one or more resource blocks transmitted in different comb patterns in the frequency domain; or 
 a plurality of sidelink feedback channel resources which occupy the resource elements from the one or more resource blocks transmitted in the different comb patterns in the frequency domain and have different cyclic shift pair sets. 
 
 
     
     
       17. The apparatus of  claim 13 , wherein:
 the one or more processors are configured to execute the processor-executable instructions and cause the apparatus to receive, from the UE, one or more sidelink control messages that schedule the multiple sidelink data messages during the time period, and 
 the one or more sidelink control messages indicate to use the first resource pool to transmit the first feedback message. 
 
     
     
       18. The apparatus of  claim 13 , wherein the resource elements from one or more resource blocks transmitted in the comb pattern in the frequency domain comprise the resource elements transmitted:
 only every second subcarrier in the frequency domain; 
 only every fourth subcarrier in the frequency domain; 
 only every sixth subcarrier in the frequency domain; or 
 only every twelfth subcarrier in the frequency domain. 
 
     
     
       19. The apparatus of  claim 13 , wherein the one or more processors are configured to execute the processor-executable instructions and cause the apparatus to select a cyclic shift to convey a value of each of the multiple feedback bits. 
     
     
       20. The apparatus of any  claim 13 , wherein:
 the first sidelink feedback channel resource occupies the resource elements from at least two resource blocks, and 
 the at least two resource blocks belong to a first interlace group of resource blocks.